Polarized switch



22, '1931. rR KELLER 1,837,188

POLARIZED SWITCH Filed Aug. 19, 1929 /NvE/vro/ ROBERT Kauf? Arrow/ff Patented Dec. 22, 1931 UNITED STATES PATENT OFFICE ROBERT KELLER, OF ENNETBADEN, SWITZERLAND, ASSIGNOR TO AKTIENGESELL SCHAFT BROWN BO'VERI & CIE., OF BADEN, SWITZERLAND, A JOINT-STOCK COMPANY OF SWITZERLAND POLARIZED SWITCH Application led August 19, 1929, Serial No. 386,827, and in Germany August 20, 1929.

This invention relates to improvements in polarized switches or so-called oscillating relays,vwhich are adapted to provide for the selective or reverse current protection of electrical apparatus.

Relays with permanent magnets have a very slight opening force and the permanent magnets lose their magnetism after a relatively short eriod of time. When the relays 1o arey equippe with or constructed as electromagnetically operated arrangements, an outside source of supply forthe voltage coilmust generally be provided, which auxiliary source it is often impracticable to arrange or even 15; impossible to obtain. n The voltage coil of an electro-magnetically operated relay usually cannot be supplied from the system to Vbe controlled because any break in the system will cause the relay to become immediately 2o ino erative.

t is, accordingly, among the objects of the present invention to provide a polarized switch orv relay in which the voltage coil of the switch is supplied directly from the sys- 26 tem to be controlled.

Another object of the present invention is to provide a voltage coil which is connected in parallel with an inductive resistance to the circuit to be controlled and which is directly y su plied from such circuit.

bjects and advantages, other than thoseabove set forth, will be apparent from the description and the drawing which shows a schematic embodiment of the present invention. n

Referring to the drawing by characters of reference, reference numeral 1 indicates one portion of an electric circuit and 2 indicates another portion of the same electric circuit.

A rectangular magnetic core member 3 is arranged in suitable relation to line 1 and is formed with pairs of projections 4, 5 and 6, 7 extending inwardly from the sides of the core 3. Line 1 of the electric circuit is wound about one leg of core 3 to form a currentr coil 8 Vwhich is connected with a fixed Contact member 9. When current flows through line l, a magnetic flux is set up through the leg of the core 3 on which the current coil 8 is wound in such manner that the flux flows across the space between the projectionsfrom 4 to 5.Y Projections 4 and 5 are accordingly polarized and ,form a north and a south pole respectively, as indicated.

Another portion of line 1 is connected with a movable contact member 10 which is mounted on a bell crank 11 supported in a suitable manner. The movable contact 10 is normally retained in contact with the fixed contact member 9, by the action or" a spring. A second current coil 12 is formed by winding the portion of line 1, Yleading from the movable contact 10 on bell crank 11, about the leg oi' core 3 on the opposite side to that portion of the core 3 which carries coil 8. Coil 12 is wound ,in the opposite direction relative to coil 8 and accordinglyproduces a magnetic field in core 3 which polarizes the projections 6 and 7 in such kmanner as to form a north and a south pole therein respectively as indicated. The magnetic flux bridges the gap between projection 6 and 7 as is the case with respect to projections 4, 5.

A voltage coil 13 is arranged between the pairs of projections or poles 4, 5 and 6, 7, and is connected across lines 1 and 2 in parallel with a resistance 14g. The voltage coil creates a magnetic ield in its immediate Vicinity and the resistance in parallel therewith prevents immediate disappearance of such field in case a short circuit or other failure occurs in the system. An armature 15 is pivotally arranged within the voltage coil 13 which magnetizes the armature to form a south pole at the end of the armature adjacent projection 5 and a north pole at the end adjacent projection 6. A lever 16 is secured to armature 15 and is provided with a roller 17 which contacts with a portion of the bell crank 11 upon which movable contact 10 is mounted.

l/Vhen the current flows in thenornial direction, core 3 is so magnetized by current coils 8 and 12 that the projections, t, 5 and 6, 7 are polarized, as shown in the drawing.

The projections on the saine side of the core are ot the same polarity and the mag,- netic flux ows across the gaps between the poles in the same direction. rlhe armature 15 is also polarized by the field of the voltage core 13 so that the south pole of the armature is formed adjacent to the south pole formed in projection 5 and the north pole of the armature is Vadj acentV the north pole formed in projection 6. The two like poles tend to repel each other and therefore tend to rotate the armature 15 in a counter-clockwise directioninsuch manner that the lever 16 is moved out of contact with the bell crank 11. Such counter-clockwiseV movement is, however, limitedv by a stop 18 which is so posi- Vtioned that armature 15 may move in acounter-clockwise direction for only a very limited distance.V The armature is retained outside of the middle magnetic position, under `normal conditions, by means oit the stop 18 so that the device may be used as a maximum current relay which will operate upon occurrence of'a forward short circuit after the voltage of coil 13 has reached zero.

Vhen the direction of the current reverses, the polarity of projections 4, 5 and 6, 7,'will also be reversed while the polarity of the i armature 15 will remain unchanged. `Under such circumstances, the poles oi' the armature 15 will be opposite in polarity to the polarity of the adjacent poles of the core and the unlike poles will'be attracted in such manner as to move the armature 15 in a clockwise direction. Armature 15, in its movement in a clockwise direction, will accordingly cause roller 17 to press `against bell crank 11 in such manner that movable contact 10 will bemoved out of contacting relation with the fixed contact 9. lt will be seen that reversal of the flow of current in an electric circuit having the present invention embodied therein, will act to yopen the circuit and that the present device will act to aid in retaining the circuit in its normally closed condition so long as the flow of current is not reversed.

Although only one embodiment of the invention has been illustrated and described, it will b e understood that various other embodiments are possible, and that various,

changes may be made without departing from the spirit of the invention or the scope of the claims.

The invention claimed is:

1. Inl a switch of the class described, a core member comprisingl four legs interlinked in such manner as to form a closed magnetic circuit of parallelogrammatic contour, current windings arranged about two oppositely disposed of said legs, a pair of projections extending into said member from each of the remaining of said legs, one pair of said projections constituting like magnetic poles oi one polarity responsive to current in said windings, the other pair of said projections constituting like magnetic poles oi polarity opposite to that of the i'irst-mentioned polarity responsive also to current in said windings, a voltage coil arranged within said member between the said yprojections constituting the respective pairsv oi' poles, an armature arranged within and polarized responsive to potential impressed uponsaid voltage coil,`said armature being adapted or frotation responsive to polarization osaid piojections, and means associated with said armature adapted to interrupt the circuits or the now or'V current in said windings and said coil responsive to rotation of said ,armature. l

'2. 1n a switch of the class described, a

core member comprising our legs inter# linked in such manner as to form a closed magnetic circuit oi parallelograiiimatic contour, current windings arranged about two oppositely disposed of'said legs, a pair of projections extending into said member from each of tnereniaining oisaid legs, one pair or said projections constituting like niagnetic poles or one polarity responsive to curient in said windings, the other pair of said projectionsconstituting like magnetic poles oi' polarity opposite torthat o tne tirst-mentioned lpolarity responsive also to current'inV said windings, a voltage coil arranged with in said member between the said projections constituting therespective pairs of poles, anYV armature arranged within and polarized re sponsive to potential impressed 'upon said voltage coil, said armature being adapted for rotation responsive to polarizationotsaid projections, and means associated with said armature adapted to interrupt the circuits for the tiow of currentin said windings and said coil responsive to rotation of said armature in one direction only.

3. In a switch ofthe class described, acore member comprising four legs interlinked in such manner as to'for'm a closed magnetic circuit of hollow parallelograinmatic con-V tour, current windings about each of two oppositely disposed of said legs, a pair'of projections extending into said member from each of the two remaining of said legs, one pair of said projections constituting lik'e magnetic poles of one or another polarity responsive to and in dependence on direction oi current in said windings, the other pair of said projections constituting like magg netic poles of `one or another polarity and opposite to that of the rst mentioned polarity also responsive to and dependence on the direction of current in said windings, a voltage coil arranged within said member iio between the said projections constituting the respective pairs of poles, an armature arranged within and polarized responsive to potential impressed upon said coil, said armature being adapted for rotation in direction in dependence on direction of current in said windings, and means associated with said armature adapted to effect interruption of the circuits for the How of current in the said windings and the said coil responsive to 1rotation of said armature in one direction on y.

In testimony whereof I have hereunto subscribed my name this 7th day of August,

ROBERT KELLER. 

